An extrusion-based 3D printer is used to build a 3D model from a digital representation of the 3D model in a layer-by-layer manner by extruding a flowable modeling material. For example, a filament of the modeling material is extruded through an extrusion tip carried by an extrusion head and deposited as a sequence of roads on a substrate in an x-y plane. In some instances, the melted material is derived from a direct deposition from a screw extruder or similar or sintered from powders (SLS) The extruded modeling material fuses to previously-deposited modeling material and solidifies upon a drop in temperature. In some instances, the position of the extrusion head relative to the substrate is then incremented along a z-axis (perpendicular to the x-y plane), and the process is repeated to form a 3D model resembling the digital representation. Movement of the extrusion head with respect to the substrate is performed under computer control, in accordance with build data that represents the 3D model. The build data is obtained by slicing the digital representation of the 3D model into multiple horizontally sliced layers. For each sliced layer, the host computer generates a build path for depositing roads of modeling material to form the 3D model.
In the printing process the holds the printing object such that the object does not move during the printing while allowing easy removal of the object when the printing is terminated.